It is estimated that 73% of Americans between the ages of 65 to 74 get cataracts. A cataract is a clouding of the eye's lens that impairs a person's vision and, if left untreated, causes blindness. As a result, each year approximately 1.4 million people in the United States alone undergo cataract surgery, whereby the clouded natural crystalline lens is removed and replaced with an intraocular lens (IOL) implant.
Surgeons implant IOLs not only as a replacement for the natural crystalline lens but also to alter the optical properties of (provide vision correction to) an eye with an existing IOL or in which the natural lens remains. IOLs often include an optically clear disk-like optic of about 6 mm in diameter, and preferably at least one flexible fixation member or haptic which extends radially outward from the optic and becomes affixed in the eye to secure the lens in position.
The optics may be constructed of rigid biocompatible materials such as polymethyl methacrylate (PMMA) or deformable materials such as silicone polymeric materials, acrylic polymeric materials, hydrogel polymeric materials, and the like. The deformable materials allow the IOL to be rolled or folded for insertion through an injector or insertion cartridge and an incision into the eye. Once within the chamber of the eye, the IOL is expulsed from the injector and returns to its original shape.
Injectors or inserters for delivering IOLs into the eye typically employ a handpiece and a removable cartridge that receives the IOL and has a hollow insertion tube or cannula through which the folded IOL is passed using a pushrod. Some inserters do without the cartridge. The inserter may be wholly or partly reusable, in which case the inserter or handpiece is usually made of some type of metal alloy that can be sterilized. Alternatively, disposable inserters made of less expensive materials, such as plastics, remain in a sterile package until ready for use. In some cases, the IOL is stored separately and transferred to a load chamber in the inserter or cartridge just prior to delivery. One particularly useful arrangement wherein the cartridge folds over an IOL is disclosed in U.S. Pat. No. 4,681,102 to Bartell. A cartridge opens to receive an IOL in a load chamber, and then folds closed and fits into an injector. A syringe-like plunger in the injector pushes the IOL from the load chamber through a tapered tube into the eye. The IOL unfolds as it emerges from the tip of the tapered tube. Another such insertion system is disclosed in Makker et al., U.S. Pat. No. 5,942,277. An example of storing an IOL in an inserter component is seen in U.S. Pat. No. 7,156,854, filed May 28, 2003. In the '854 patent, a nozzle portion 12 along with a removable stop 26 retains the IOL therein during storage and has internal ramps that assist in folding the IOL optic during an implant procedure. Also, U.S. Patent Publication No. 2008/0058830, filed Jul. 17, 2007, discloses a number of configurations for pre-loading IOLs for transfer to an insertion apparatus, and is expressly incorporated herein. Another preloaded insertion system is illustrated in U.S. Patent Publication No. 2009/0318933, filed Jun. 23, 2008, which is hereby incorporated by reference in its entirety.
Despite the advances in the area of insertion devices, there remains a need for devices and systems that increase the ease of use of inserters, including facilitating the insertion of IOLs, while reducing the risk of damage to both the insertion device and the IOL.